Thread tensioning apparatus for twisting spindles



7 W. LENK June 18, 1957 THREAD TENSIONING APPARATUS FOR TWISTING SPINDLES Filed Nov, 8, 1955 v T m.

. z m mm m w A United States Patent THREAD TENSIONIN G APPARATUS FOR TWISTING SPINDLES Walter Lenk, Remscheid-Lennep, Germany, assignor to Barmer Maschinenfahrik Aktiengesellschaft, Wuppertal, Oberbarmen, Germany Application November 8, 1955, Serial No. 545,609

Claims priority, application Germany November 8, 1954 9 Claims. (Cl. 242147) This invention relates to thread tensioning apparatus for twisting spindles, especially multiple thread twister spindles. More particularly, the invention relates to thread tensioning apparatus mountable on a bobbin and including a guide member having a bore or opening therethrough and a tensioning wire mountable on the guide member for tensioning thread or yarn-unwinding from the bobbin and for rotation during the unwinding.

This application is a continuation-in-part of and constitutes a further improvement over my copending patent application, Serial No. 457,037, filed September 20, 1954, now Patent 2,762,583, issued September 11, 1956, the disclosure of which is incorporated herein and made a part hereof by reference as fully as if set forth herein in its entirety Thread or yarn tensioning appliances for twisting spindles have been proposed which, however, have suffered from several drawbacks. In the above-identified application, new and improved thread tensioning apparatus which overcomes the prior difliculties is described. Yarn tensioning apparatus for twisting spindles, especially of the cable type, is disclosed which insures correct unwinding or drawing of the thread to be twisted from the bobbin, imparting a small and uniform tension to the thread due to its high sensitivity.

In the apparatus, a guide member, also referred to as a yarn drawing or Winding member, is provided which is mountable on the bobbin in fixed position. The guide member has an axial bore or thread passage or opening therethrough, extending from the outer or upper end of the guide member and communicating with the chamber within the tubular bobbin. A tensioning wire in the form of a hairpin or the like is also provided, and it is rotatably mounted on the guide member with one leg in the bore and the other outside of the guide member for rotation therearound while engaging the thread. The tensioning wire serves to impart tension to and guide the thread which is being unwound from the bobbin, which may be, for example, a cop. The thread being unwound next passes through the bore or thread passage in the guide member and then through the chamber of the bobbin to the twisting spindles. The twisting spindles exert tension on the thread which unwinds it from the bobbin. As the thread unwinds, it rotates the tensioning wire.

In the apparatus, one leg of the tensioning wire is inserted in the bore of the guide member and is rotatable therein with clearance for passage of the thread. The remaining leg of the wire is supported on the outer surface of the guide member, on a bulge thereon, for rotation on the bulge. An inwardly bent portion of the outer leg is located in an annular peripheral groove or channel on the guide member, to maintain the wire in position during operation and when threading the apparatus. The bulge may be adjacent or form a side wall of the groove, and it supports the wire above the outer end or head of the guide member and clear of the thread passing therearound. The outer leg of the tensioning wire has a thread guide thereon, preferably formed by suitably bending the wire.

The thread tension is regulated by the tensioning wire, which rotates due to the unwinding of the thread from the bobbin and exerts a tensioning pull on the thread. With lower thread tension from the twisting spindle, the outer leg of the tensioning wire lags behind the point of separation of the thread from the bobbin a certain distance, and there is then a thread reserve for a subsequent increase in tension from the spindle. With greater thread tension, there is less lag, and when tension from the spindle decreases, the wire lags more to take up the slack. These effects impart to the thread a uniform small tension which results in the even supply of thread to the twisting spindles.

The above-described bulge also exerts a braking effect on the rotating wire which produces corresponding tension on the thread. The degree of tension may also be varied by varying the' weight of the tensioning wire, by afiixing a weight to the wire, by causing a magnet to act on the wire, and in other ways.

The construction illustrated in the above application has proven to be very useful in practice. In certain cases, however, especially when the thread is very fine or when the thread is fed at a particularly high rate, the tension regulator should be very sensitive and must react to the smallest differences in tension. In these cases, difliculties may be encountered due to the length of the outer leg of the tensioning wire and the location of the thread guide at its end, because the mass effects of the rotating leg, especially the influence of centrifugal force, become too great and reduce the sensitivity of the thread tension regulation.

It is therefore an object of the present invention to provide a new and improved thread tensioning apparatus which is especially sensitive.

Another object is to provide an apparatus especially adapted for processing very fine threads, particularly While unwinding at a high speed, in a reliable and trouble-free manner.

An additional object is to provide an apparatus wherein the acceleration and deceleration energies of the tensioning wire are. reduced to permissible or unobjectionable limits.

A particular object is to reduce the centrifugal eifects of the rotating guide leg.

A further object is to provide an apparatus wherein the bearing friction of the tensioning Wire is very small.

A further particular object is to provide an apparatus wherein the rotating guide leg of the tensioning wire has a reduced mass, e. g., is relatively short, and is constructed to minimize acceleration and deceleration effects or render them nugatory.

Another particular object is to provide an apparatus wherein the thread guide on the tensioning wire is located near the thread entrance to the guide member, with no necessity for the use of wire portions which extend further, adding to the mass and to the centrifugal effects. These and other objects, advantages and functions of the invention will be apparent on reference to the specification and to the attached drawings, in which like parts are identified by like reference characters in each of the views, and in which:

Fig. 1 is a schematic side elevational and partly sectional view with parts broken away of one embodiment of the thread tensioning apparatus of the invention, illustrating a guide member mounted on a bobbin and one form of the tensioning wire mounted on the guide member;

Fig. 2 is a top plan view of the tensioning wire illustrated in Fig. 1; and

Figs. 3 and 4, and 6, 7 and 8, and 9 and are views corresponding to Figs. 1 and 2, respectively, illustrating four additional embodiments of the tensioning wire.

The thread tensioning apparatus of the invention includes a longitudinally bored guide member mountable on a bobbin and having a peripheral groove adjacent its outer end, a hairpin-like tensioning wire rotatably mountable on the guide member, one leg of thewire being rotatable in the bore of the guide member, the remaining leg of the wire being formed to rotatabiy seat in the groove on a wall of the groove, and a thread guide on the remaining leg. The tensioning wire is constructed for minimizing centrifugal effects and bearing friction. Thus, the thread guide is located between the mouth of the guide member and the wall of the groove, the groove be ing adjacent the outer end of the guide member. The result is an outer rotating leg having considerably reduced centrifugal eifects and preferably also reduced weight and thereby also reduced bearing friction. The remaining leg is preferably relatively short and formed to rotatably seat its free extremity in the groove.

Referring to the drawings, a bobbin spool or tube 1 is illustrated in Fig. l with a conical or frusto-conical guide member, or yarn winding member 2 fixedly mounted thereon. The guide member 2 is provided with an axial longitudinal vertically extending bore or thread passage 3 extending therethrough and communicating with the interior or the chamber of the bobbin 1. At the outer, upper or head end of the guide member 2, a smooth annular protective collar or cap 4 is secured and forms a part of the guide member. The collar provides a mouth 5 at the end of the guide member 2 and provides a rounded lip thereon. The collar is preferably formed of an abrasion-resistant material such as glazed ceramic material, hard chromium plated and polished steel, or the like, to permit the thread 6 to slide over the lip easily and to reduce wear. The remainder of the guide member 2 may then be constructed of cheaper, less abrasion-resistant material.

The guide member 2 is secured to the bobbin 1 by an elastic ring 7 or the like, which is positioned in a corresponding groove on the outer surface of the guide member 2 and adjacent its base 3. The ring 7 also contacts the bobbin 1 at one or more points corresponding to openings in the wall of the guide member which cornmunicate with the surface of the bobbin. An annular protective cover 9 is secured to the exposed or outer edge at the inner or lower end or base 8 of the bobbin 2 to form a protective surface on the bobbin for the passage of thread thereover. This cover is likewise preferably constructed of abrasion-resistant material and performs the same functions.

A hairpin-like tensioning wire 10 or the like is rotatably mounted on the guide member 2. The wire is preferably a single continuous piece and includes a substantially straight inner leg 11 joined by a reverse bend 12 to a short outer guide leg 13. The straight leg 11 is positioned in the bore 3 of the guide member 2 with sufiicient space or clearance remaining therein for the leg to rotate and for the thread to pass freely through the bore. The outer, short leg 13 is rotatably seated in a smooth peripheral annular groove or channel 14 on the guide member and on a lower or inner side wall 15 thereof. The wire 10 is thereby supported with its reverse bend 12 and the remainder of the wire closelyadjacent while spaced from or out of contact with the lip formed by the collar 4, where the thread 6 passes around the collar, preventing pinching of the thread.

The outer leg 13 is formed or bent to provide a thread guide, eyelet, loop or bend 16, and an inwardly bent portion 17 at the free end of the wire which rests in the groove 14 on the lower side wall 15. The wire member 10 is resilient metal, and the legs 11 and 13 are spread to mount the wire, after which the bent portion 17 springs into position in the groove 14. The groove holds the 4 wire so that it will not be removed when the threading wire is inserted or during operation.

The groove 14 is closely adjacent the outer or upper end of the guide member 2 and in close proximity to the axis of the bore 3. In this manner, with the free end of the outer leg 13 seated in the groove, the outer leg is short relative to the earlier constructions and is arranged substantially completely above the lower side wall 15 and proximate or near to the axis of the bore. Centrifugal and other mass effects are then greatly reduced. The groove 14 is preferably formed by joining a protective collar such as 4 to the body 18 of the guide member having a contracted neck and having a shoulder 19 adjacent the outer end of the body and corresponding to the lower side wall 15, as illustrated. However, the guide iember 2 may be formed in one piece with a. peripheral groove thereon.

The thread guide or loop 16 in the embodiment of Figures 1 and 2 is substantially horizontal or normal to the axis of the guide member 2, and it supports the thread 6 outwardly or laterally of the guide member, oif of its side 20. The thread guide can be arranged in other positions and be formed in other ways, as illustrated in Figures 3 through 10 at 21 through In each case, the thread guide is preferably ofiset laterally from the outer leg 13 and 25 through 28, that is, so that the thread 6 passing through the guide and over the top collar will be clear of the remaining part of the outer leg and will not wind around it or around the top of the guide member 2. Themanner in which this may be accomplished is illustrated by Figures 2, 4, 6, 8 and 10.

In the embodiments of Figures 5 through 10, the thread guide 22, 23 or 24 is formed in the respective inwardly bent portion 29, 30 or 31. As illustrated in Figures 5, 6, 9 and 10, the free end 32 or 33 of the wire may be bent or spread laterally from the thread guide to facilitate threading.

in operation with the new thread tensioning apparatus, as illustrated in Figures 1 and 2, the thread 6 being supplied to the twisting spindle is unwound from the bobbin 1, passes over the protective ring 9 at the base 8 of the guide member 2, passes through the thread guide 16 and over the protective collar 4, on the head of the gride member, and then passes through the axial bore 3 and through the interior of the bobbin 1 to the twisting spindle.

In the improved construction, the thread guide 16 is located between the mouth 5 of the guide member, formed by the head collar 4, and the lower or inner side wall 15 of the groove 14. The outer leg 13 is bent inwardly as at 17 and terminates longitudinally in the bent portion, to rest in the groove 14. By the expression terminates longitudinally is meant that the leg 13 extends substantially no further in the direction of the leg, although the wire may be doubled back or up as illustrated in Figures 5, 6, 9 and 10. Thus, the longitudinal terminus or free extremity includes both the inner edges 34- and 35 of the effective ends of the outer legs 26 and 28 in Figures 5, 6, 9 and 10, and the edges 36, 37 and 38 of the free ends of the outer legs 13, 25 and 27 of Figures 1, 2, 3, 4, 7 and 8.

The free end or the effective end of the outer leg 13 or 25 through 28 thus rotates in the groove 14- and on the side wall 15 due to the threads unwinding around the bobbin 1. The tensioning wire 10 acting through the outer leg guides the thread and keeps it under a small uniform tension. Since the centrifugal and other mass effects of the outer leg construction have been greatly reduced, the acceleration and deceleration energies are reduced to permissible limits and hte bearing friction is very small. The sensitivity of the thread tensioning apparatus is greatly increased, and this is highly important for handling very fine threads in a trouble-free operation, especially at high unwinding speeds.

The invention is hereby claimed as follows:

1. Thread tensioning apparatus for twisting spindles comprising a longitudinally bored guide member mountable on a bobbin and having a peripheral groove adjacent its outer end, a hairpin-like tensioning wire rotatably mountable on said guide member, one leg of said wire being rotatable in the bore of said guide member, the remaining leg of said wire being formed to rotatably seat in said groove on a wall thereof, and a thread guide on said remaining leg between the mouth of said guide member and said wall.

2. Thread tensioning apparatus for twisting spindles comprising a longitudinally bored guide member mountable on a bobbin and having a peripheral groove adjacent its outer end, and a hairpin-like tensioning wire rotatably mountable on said guide member, one leg of said wire being rotatable in the bore of said guide member, the remaining leg of said wire being relatively short and being formed to rotatably seat its free extremity in said groove on a wall thereof, said remaining leg also being formed to provide a thread guide therein.

3. Thread tensioning apparatus for twisting spindles comprising a longitudinally bored guide member mountable on a bobbin and having a peripheral groove adjacent its outer end, and a tensioning wire mountable on said guide member, said wire comprising a substantially straight leg rotatable in the bore of said guide member and joined by a reverse bend to a short leg, said short leg being bent inwardly and terminating longtiudinally in the bent portion, said bent portion being formed to rotatably seat in said groove on a wall thereof, and said short leg also being bent to provide a thread guide therein.

4. Thread tensioning apparatus for twisting spindles comprising a longitudinally bored guide member mountable on a bobbin with the bore extending vertically and having a horizontal peripheral groove adjacent its upper end andin close proximity to the axis of said bore, and a tensioning wire mountable on said guide member, said wire comprising a substantially straight leg rotatable in the bore of said guide member joined by a reverse bend to a second leg, said second leg being bent inwardly with the innermost extremity formed to rotatably set in said groove on the lower side wall thereof, said second leg also being bent to provide a thread guide therein supporting thread outwardly of said guide member, said second leg being arranged substantially completely above said side wall and proximate to said bore axis.

5. Apparatus as defined in claim 1 including a protective cover on the exposed edge of said guide member at its inner end.

6. Apparatus as defined in claim 1 wherein said guide member comprises a longitudinally bored member having a shoulder adjacent its outer end and a protective collar mounted on said outer end and forming said peripheral groove with said shoulder.

7. Apparatus as defined in claim 3 wherein said thread guide is provided in said bent portion.

8. Apparatus as defined in claim 3 wherein said thread guide is olfset laterally from said short leg.

9. Apparatus as defined in claim 3 wherein the free end of said short leg is bent laterally from said thread guide to facilitate threading.

No references cited. 

